疏水/亲水大孔PDVB/PAEMIPN 树脂对香兰素的吸附性能

采用分步悬浮聚合法制备了具有疏水性能的聚二乙烯基苯(polydivinylbenzene, PDVB)为第一网, 具有亲水性能的聚丙烯酰乙二胺(polyacrylethylenediamine, PAEM)为第二网的疏水/亲水大孔聚二乙烯基苯/聚丙烯酰乙二胺(PDVB/PAEM)互穿聚合物网络(interpenetrating polymer networks, IPN), 研究这类疏水/亲水IPN组成的树脂对吸附质的吸附热力学和吸附动力学; 测定了该树脂对香兰素在不同温度下的吸附等温线, 吸附等温线符合Freundlich等温吸附方程, 利用热力学函数关系计算出了吸附焓、自由能和熵变. 实验表明, PDVB/PAEM IPN树脂中疏水性的PDVB网具有疏水作用吸附能力, 亲水性的PAEM网具有氢键作用吸附能力. 吸附动力学数据符合Lagergren二级速率方程, 颗粒内扩散是吸附速率的主要控制步骤, 可采用HSDM模型加以描述.

Adsorption Performances for Vanillin from Aqueous Solution by the Hydrophobic-Hydrophilic Macroporous Polydivinylbenzene/ Polyacrylethylenediamine IPN Resin

Hydrophobic-hydrophilic macroporous polydivinylbenzene/polyacrylethylenediamine interpenetrating polymer networks (PDVB/PAEMIPN) were prepared by the sequential suspension polymerization method. These were composed of two networks, of which one was hydrophobic (PDVB) and the other was hydrophilic (PAEM). The objective of this work was to study the adsorption thermodynamics and adsorption kinetics of this hydrophobic-hydrophilic IPN. The focus was on adsorption isotherms of vanillin at different temperatures, and these fit well into the Freundlich adsorption isotherm. The isosteric adsorption enthalpy, adsorption Gibbs free energies and the adsorption entropy could be calculated according to thermodynamic functions. The hydrophobic PDVB in the PDVB/PAEM IPN resin adsorbs through hydrophobic interaction while the hydrophilic PAEM adsorbs by hydrogen bonding. The adsorption kinetic data was fitted to the Lagergren pseudo second order rate equation. Intraparticle diffusion was the rate controlling step and could be described by HSDMmodel.